Image forming apparatus

Abstract

An image forming apparatus comprising an image forming unit that forms an image on a sheet, a sheet feeder that feeds the sheet to the image forming unit, a detector that detects a width of the sheet, a setting unit that is operated by a user to input a width and a length of a nonstandard-size sheet, a determination unit that determines whether the width of the nonstandard-size sheet detected by the detector and the width of the nonstandard-size sheet inputted by the user to the setting unit differ from each other, when the image is printed on the nonstandard-size sheet and a controller that controls the image forming unit to form the image, based on the width of the sheet detected by the detector and the length of the sheet inputted by the user to the setting unit, when the determination unit determines that the detected width and the inputted width differ from each other.

1 . An image forming apparatus comprising:
 an image forming unit that forms an image on a sheet;   a sheet feeder that feeds the sheet to the image forming unit;   a detector that detects a width of the sheet;   a setting unit that is operated by a user to input a width and a length of a nonstandard-size sheet;   a determination unit that determines whether the width of the nonstandard-size sheet detected by the detector and the width of the nonstandard-size sheet inputted by the user differ from each other, when the image is printed on the nonstandard-size sheet; and   a controller that controls the image forming unit to form the image, based on the width of the sheet detected by the detector and the length of the sheet inputted by the user to the setting unit, when the determination unit determines that the detected width and the inputted width differ from each other.   
   
   
       2 . The image forming apparatus according to  claim 1 , wherein the image forming unit comprises a fixing roller that fixes the image onto the sheet, the fixing roller includes a first heating unit that heats a part of an area of the fixing roller and a second heating unit that heats a larger area of the fixing roller than the part of the area, and the controller controls where the fixing roller is heated using the first and second heating unit, based on the width of the sheet detected by the detector. 
   
   
       3 . The image forming apparatus according to  claim 2 , wherein:
 the first heating unit heats a central area of the fixing roller in a longitudinal direction of the fixing roller, and   the second heating unit heats the entirety of the fixing roller in the longitudinal direction of the fixing roller.   
   
   
       4 . The image forming apparatus according to  claim 1 ,
 wherein the sheet feeder comprises:   a first sheet cassette that houses standard-size sheets; and   a second sheet cassette that houses nonstandard-size sheets.   
   
   
       5 . The image forming apparatus according to  claim 4 ,
 wherein the first and second sheet cassettes include the detector respectively.   
   
   
       6 . The image forming apparatus according to  claim 1 ,
 wherein the detector detects the width of the sheet by reading a resistance of a variable resistor.   
   
   
       7 . A method of forming an image comprising the steps of:
 feeding a sheet to an image forming unit;   forming an image on the sheet;   detecting a width of the sheet that the image forms;   inputting a width and a length of a nonstandard-size sheet that the image forms;   determining whether the detected width of the nonstandard-size sheet and the inputted width of the nonstandard-size sheet differ from each other, when the image is printed on the nonstandard-size sheet; and   controlling the image forming unit, based on the detected width of the sheet and the inputted length of the sheet, when the detected width and the inputted width differ from each other.   
   
   
       8 . A method of forming an image comprising the steps of:
 feeding a sheet to an image forming unit;   forming an image on the sheet;   detecting a width of the sheet that the image forms;   inputting a width and a length of a nonstandard-size sheet that the image forms; and   determining whether the detected width of the nonstandard-size sheet and the inputted width of the nonstandard-size sheet differ from each other, when the image is printed on the nonstandard-size sheet, and if so, forming an image based on the detected width of the sheet.